Teleprinter assembly

ABSTRACT

Each of a plurality of self-restoring horizontally spaced apart print hammers selectively is driven lineally toward a printing position in response to movement of the armature of an electromagnet. The electromagnets are disposed in a pair of spaced apart banks, their armatures extending inwardly and providing a plurality of aligned working inner ends as agents for application of electromagnetic energy. A circuit card is physically secured and electrically connected to the coil assembly of each of the electromagnets of each bank and has a plurality of aligned apertures enabling passage and rocking movement of the corresponding armatures. The circuit cards are vertical and are disposed in horizontally extending parallelism, the working inner ends of said armatures being disposed therebetween. A circuit board is physically secured and electrically connected to said cards with which it is orthogonally disposed.

[ Jan. 15, 1974 United States Patent [1 1 Kearney Primary ExaminerClydeI. Coughenour Attorney-J. L. Landis et a1.

[ TELEPRINTER ASSEMBLY [75] Inventor: James F. Kearney, Oak Park, 111.

Assignee: Teletype Corporation, Skokie, 11].

ABSTRACT [22] Filed: Sept. 18, 1972 [21] Appl. No; 290,192

Each of a plurality of self-restoring horizontally spaced apart printhammers selectively is driven lineally toward a printing position inresponse to movement of the armature of an electromagnet. Theelectromagnets are disposed in a pair of spaced apart [52] U.S. Cl.101/93 C, 317/101 CW, 317/113 banks, their armatures extending inwardlyand providing a plurality of aligned working inner ends as agents forapplication of electromagnetic energy. A circuit card is physicallysecured and electrically connected to the coil assembly of each of theelectromagnets of each bank and has a plurality of aligned apertures en-[56] References Cited UNITED STATES PATENTS abling passage and rockingmovement of the corre- 101/93 C sponding armatures. The circuit cardsare vertical and are disposed in horizontally extending parallelism, the317/113 working inner ends of said armatures being disposed 3 7/101therebetween. A circuit board is physically secured and electricallyconnected to said cards with which it is orthogonally disposed.

3,255,693 6/1966 Eissfeldt et 3,291,040 12/1966 Holloran et al.......

3,445,728 5/1969 Jorgensen et a1...

3,437,882 4/1969 Cayzer.........................,......

FOREIGN PATENTS OR APPLlCATlONS 793,785 4/1958 Great Britain.........317/101 CW 3 Claims, 5 Drawing Figures 1 TELEPRINTER ASSEMBLY BACKGROUNDof the INVENTION The present invention relates to signal responsiveimpact printers. More particularly, the invention relates toelectromagnetic assemblies for controlling print hammers inteleprinters.

In a class of printer with which the present invention is concerned, aplurality of print hammers corresponding to the number of printingstations in a line of copy are responsive to selectively actuatedelectromagnets for printing. The application Ser. No. 292-003 of Egon S.Babler, contemporaneously filed herewith, and assigned to the assigneeof the present application, is directed to printers in said class. Thisaforesaid contemporaneously filed application is incorporated herein byreference.

In the printer shown in said application, impelling means for printhammer control is of the type disclosed in U. S. Pat. No. 2,927,960,issued to W. P. Byrnes, Mar. 8, 1960. However, the patented apparatushas been improved according to said application and others referred totherein to lower the mechanical inertia of the impelling means as wellof its print hammers. Resultantly, the speed of printing response can beincreased to a level which is compatible with handling, at an optimumrate, the output from a buffer storage, for example, between incomingdata and a printing mechanism. Moreover, printer costs have beenminimized in the printer shown in said application by providing theelectromagnets having armatures with inner working end portions alignedin a single straight array. On the other hand, the electromagnetsthemselves are arranged in a pair of banks disposed on opposed sides ofthe aligned working ends of the armatures.

Further improvement for minimizing costs in printers of the indicatedclass can be directed to simplifying the means for transferring logicgenerated signals to the electromagnets for effecting armature control.

It is an object of the invention to simplify the imposition of logic ina high speed signal responsive printer having simultaneously actuateableprint hammers responsive to electromagnets, particularly by providing animproved assembly of electromagnets and armatures for operating impactprinters of the type described.

SUMMARY of the INVENTION The foregoing, and other objects of theinvention which will become apparent from the ensuing detaileddescription, are attained in an impact printer having a lineal array ofprint hammers which are responsive, respectively, to electromagneticallycontrolled armatures. The armatures are disposed in opposed banks andhave inner portions, aligned, each with the other, for control of saidhammers. This application particularly concerns an improved assembly ofelectromagnets and armatures for such printers, wherein operatingelectromagnets for the printer are arranged vertically beneath a printerframe in two horizontal rows, and the armatures comprise pivoted armsmounted vertically beneath the electromagnets and having interleavedinner operating ends terminating in a common vertical plane. Theelectromagnets include vertically arranged magnet cores having bobbinassemblies slideably received thereon, and electrical operating coilswound on the bobbin assemblies.

The mounting assembly includes a pair of printed circuit cards mountedvertically in the frame between the cores and the operating ends of thearmatures. One card is associated with each row of electromagnets andarmatures, and the cards extend downward from positions above the topsof the bobbins to positions below the armatures. The cards haveelongated vertically disposed slots therethrough, through which thearmatures extend and which permit pivoting movement of the armatureswhen the coils are operated. A snap-in connecting device is provided forphysically connecting each bobbin assembly to its associated circuitcard in the required position in its row, the cards serving tovertically position the bobbin assemblies on the cores at the desiredaltitude. Each card has a plurality of printed conductors havingportions extending vertically downward to the bottom of the card andterminating in terminal pads along the bottom of the card, and theconductors are arranged on the cards opposite to the bobbins and areelectrically connected to the leads of the coils. Individual operatingcircuit components for the electromagnets are connected to the terminalpads at thebottom of the cards.

BRIEF DESCRIPTION of the DRAWINGS In the ensuing detailed description ofthe invention, reference is had to the accompanying drawings on which:

FIG is a perspective view of an impact printer embodying anoperatingassembly according to one form of the invention, parts beingbroken away and DETAILED DESCRIPTION of the INVENTION Referring now toFIG. 1 of the drawings, the impact printer shown in generally designated10. It has a pair of spaced apart pulleys l2 and 14 about which anendless carrier 16 is trained for translocating a plurality of pallets18 by movement in a circuitous path. A plurality of dies 17 (FIG. 2) arecarried on the front faces of the pallets. The pallets, except forpossibly the terminal pallets in a font, are uniformly dimensioned anduniformly and equally spaced apart axially of the carrier. When dies 17comprise alphanumeric characters, two or more successive fonts axiallyof carrier 16 may enable longer line output.

Carrier 16 and pallets 18, together with attendant elements (omittedfrom the drawings) may be substantially as shown and described in thecopending application of Francis E. Huntoon and James F. Kearney, Ser.No. 208,198, filed Dec. 15, 1971, and assigned to the assignee of thepresent application now US. Patent 3,742,848, issued July 3, 1973. Inaccordance with said last named copending application, which isincorporated herein by reference, the plane in which parallel axes ofpulleys l2 and 14 are disposed and the vertical section of web 22 onwhich printing is about to occur are orthogonally disposed. Sucharrangement generates a loop in the carrier with an upper or printingcourse 21 and a lower or return course 23 which are disposed in a planewhich is substantially parallel to web section 20.

In the exemplary printer l0, pulley 12 is an idler sheave while pulley14 is a drive sheave secured to a shaft 24. Driving torque continuouslyis transmitted to said shaft from an operating prime mover means, hereinshown as a motor 26, through a drive train generally designated 27. Thelatter herein includes an impeller shaft 30. This shaft has opposed endportions journalled in opposed side walls 28 of the chassis or frame 29(FIG. 2) of printer 10, and it is continuously driven in the directionindicated by arrow 31 during printer operation.

A segment 32 of ribbon 34 is disposed in a plane substantially parallelto carrier course 21 between and spaced slightly from face 36 to websection 20 and the pallets 18 supported from said last course. Theribbon is trained about a plurality of ribbon guides 38 which are spacedapart such that the ribbon assumes a generally rectangular configurationin a horizontal plane. Opposed end portions of the ribbon are secured toa pair of adjoining ribbon spools 40 and 42 which alternately functionfor ribbon supply and accumulation. They alternately are driven inopposite angular directions, by a spool control mechanism 44, thedetails of construction of which form no part of the present invention.Mechanism 44 is connected to motor 26 through a pulley wheel 46 which issecured on an end portion 47 of shaft 24 for driving the spool controlmechanism through a pulley belt 48.

A clutch 50, which may be conventional, is mounted for releaseablysecuring a split shaft section 52 to the shaft 24 from which saidsection extends axially. Selective actuation of the clutch may beeffected through logic which may be conventional and the details ofconstruction of which form no part of the invention. Thereupon,operating means, being a drive train generally designated 54, advancesweb 22, in the direction shown by arrow 56, a line-at-a-time. Suchadvancement results from incremental rotation of a worm gear 58 fordriving a pulley belt 60 intermittently angularly to move a cylindricalroller 62. Roller 62 is disposed transversely of and adjacent to thepath of web movement for frictionally engaging web 22 and in cooperationwith other components (not shown), intermittedly drawing said web fromits supply source (not shown) about a guiding cylinder 64, as said webis advanced.

lmpelling means comprises an array of radially symmetrical impellers 66(only representative ones of which are shown in FIG. 1). The impellingmeans herein are substantially as shown and described in two commonlyassigned copending applications of Egon S. Babler. Ser. Nos. 268,236 and268,238, filed July 3, I972, which are incorporated herein by reference.Accordingly, each impeller is comprised of a plurality of radial,equiangularly spaced arms or impelling elements 68, (FIG. 2), theimpellers being concentrically secured to shaft 30 for rotationtherewith in the direction shown by arrow 70 in the exemplaryembodiment. The impellers are axially or horizontally spaced such thateach is disposed in substantially horizontal alignment with a printingstation on an imaginary line extending horizontally across web section20. A plurality of circular shims 72 are disposed between impellers 66and define a plurality of horizontally aligned annular chambers, as moreparticularly defined in said application Ser. No. 268,238.

lmpacter means for printing comprise a plurality of equally spaced apartprint hammers 76 (only some of which are shown in FIG. 1) disposedbehind back face 78 (FIG. 2) of web section 20. The impacter meansherein may be substantially as shown and described in said copendingBabler applications Ser. Nos. 268,236 and 268,238, as well as in anadditional commonly assigned Babler application Ser. No. 268,237 filedJuly 3, 1972, which is incorporated herein by reference. Accordingly,each hammer is aligned with the others in a horizontal array parallel tothe alignment of impellers 66. Each hammer also is aligned with, thoughspaced from, and disposed out of the path of movement of an associatedimpeller by which it can be selectively driven in a lineal path,perpendicularly to web section 20, between a normal or non-printingposition (FIG. 1) and a printing position (not shown) against said backface 78 (FIG. 2).

The dies 17 on pallets 18 in course 21 and hammers 76 are disposed at acommon horizontal level; and said pallets and their dies whentranslocated move in a path parallel to the hammer array for printing.Thereby, each pallet 18 and groups thereof can be moved successivelyinto printing positions in horizontal alignment with successive hammers76 and groups thereof. The force generated by each impeller 66 forurging web section 20, ribbon segment 32 and any aligned dies 17 intocontact is of sufficient magnitude for printing by forming an image ofeach such die on web face 36. In the exemplary embodiment of theinvention herein, the hammers are associated with and reciprocativelyarranged in the chassis or framework 29 by means and in the mannerdisclosed in said copending application Ser.

A horizontal bumper, in the form of a rod 80 (FIGS. 1 and 2), isdisposed parallel to shaft 30 has opposed ends secured in the chassisside walls 28. Said rod extends through horizontally aligned slots 82 inthe hammers 76 for limiting horizontal hammer movement.

A leaf spring 84 (FIGS. 1 and 2) of general vertical orientation andassociated with each hammer 76, is included in hammer driving means. Thelower end portion of all of springs 84 are integrally fashioned with ahorizontal front wear plate 83 which is rigidly secured to a frontchassis plate 86. An upper end portion of each spring 84 is engaged in adownwardly opening slot 88 in the printing head 77 of each hammer 76.Each spring 84 has a slightly tensioned condition (FIG. 2) during whichits hammer is in its rearward or most remote non-printing position, anda most tensioned condition (not shown) during printing for urging orrestoring its hammer to non-printing position.

Each impeller 66 is adapted to move a printingly associated and alignedhammer 76 through the agency of an interponent 90. In the preferredembodiment of the invention, printing is effected and the assemblies ofthe interponents as well as the other parts of printer 10, includingmeans for controlling and liberating the interponents are, as shown anddescribed in said application Ser. No. 268,238. In accordance therewith,the interponents are disposed in general horizontal alignment and eachhas: (I) a first or upper position in which it is in a projectedcondition, with its upper free end portion disposed in the path ofmovement of associated impeller arms 68 for transmitting force from itsimpeller 66 to an aligned hammer 76 in consequence of which printingoccurs, and (2) a lower, non-printing, or second position in which saidinterponent has fallen and is removed from the impeller path.

As shown and described in said last named application, each interponent90 intermittently is controlled by an assembly comprised of amagnetically elevateable armature 92 and an electromagnet 94 (FIG. 2).Any suitable logic, (forming no part of the present invention) which maybe conventional, may be employed for energizing selected electromagnets94. In consequence of energization of any electromagnet its armaturewill be rocked, magnetomotively, against the restoring bias of itscontractile spring 96, from its position shown (FIG. 2) upwardly to alatched position (not shown).

Correspondingly, an affected interponent 90 will be thrust upwardly(from its FIG. 2 position) into its first position or projectedcondition (not shown) between a pair of adjoining impeller arms 68against the lowering bias of an associated spring 98 (FIG. 2) whichbecomes tensioned upon upward movement of its interponent. Ensuingly, anupwardly thrust interponent will be engaged by one of the circuitouslytravelling impeller arm 68 of its impeller; and said interponent thenwill be rocked into engagement with an associated hammer 76 to effectmomentum transfer and translation of impeller torque into a lineal forcefor printing. Both momentum transfer and restoration of each interponent90 to its second position (FIG. 2) following momentum transfer, as wellas the conditioning of interponents for repeat cycles are as shown anddescribed in said last named copending application.

In the exemplary printer 10, though the spacing between the centers ofthe hammers 76 need not be the same as the spacing between the centersof pallets 18 in course 21, the spacing of said hammers as well as theirdimensions, mode and sequence of operations, and printing with printeris as shown and described in said copenidng application Ser. Nos.268,236 and 268,238. Moreover, adjustment of impact of the hammerspreferably is as shown and described in said copending application Ser.No. 268,237. Therefore, pallets 18 are mounted on the inner ends ofshanks 100 (FIG. 2) whose outer ends are disposed against a backup bar(not shown); and said shanks are disposed in a horizontal plane and areremovably mounted in carrier 16, extending transversely therethrough.

The assembly of the electromagnets 94 are as shown and described in saidcontemporaneously filed application Ser. No. 292,003. In the exemplaryembodiment, each electromagnet 94 comprises a pair of electricallyinterconnected wire coils 104A and 1048 of a windings member 104 (FIGS.2 and 5). The coils, respectively, of each pair are circumposed aboutlegs 106A and 106B of a pair thereof comprising a corresponding magneticcore 106. The electromagnets 94, which is to say, the cores, and theirwindings members, are uniformly horizontally spaced apart and disposedin a pair Each core 106 has an upwardly projecting anchoring lug orshank 107 (only one is shown in FIG. 2) which is firmly secured in arespective one of a plurality of holes 112 formed in a horizontal wall114 of chassis 29. Said holes (only'one of which is shown) are alignedin said banks 108 and 110, the alignment of the holes in each bank beingparallel to the hole alignment in the other bank and extending along andparallel to a re spective one of-the chassis plates and 86. Herein, andas disclosed in at least one of my aforesaid copending applications,each core and its hole 112 in one of the banks 108 and 110, thoughequally spaced from adjoining cores member and holes in the same bank,are offset horizontally-from the corresponding core and hole in theopposed bank by a distance equal to half the spacing between adjacentcores and their holes.

Each armature 92 has an outer portion 116 (FIG. 2) with an upwardlyprojected extension 118. Each outer portion passes below the chassis 29and extends outwardly therefrom through one of a plurality of slots 120in a chassis supported bracket 122, each outer portion being guidinglydisposed in one of the slots 124 in said bracket. Each armature also hasan inner portion 126 which terminates in a flat stand 128. Thearrangement of the armatures in offset banks 108 and is such that all ofthe stands 128 are disposed in general alignment, horizontally, witheach armature being vertically aligned with an associated one of saidimpellers 66.

A flat broad latching section 130 of magnetic material on each armature92 is disposed below and in alignment with the lower ends of a pair ofcore legs 106A and 1068 of a corresponding core 106 to which suchlatching section is drawn upon energization of an associated windingsmember 104. Accordingly, each armature has a first or latched condition(not shown) in which the latching section 130 of such armature ismagnetically held against its core 106 and a second, nonprinting orreleased condition (FIG. 2) in which a corresponding spring 96 biasesits armature away from a magnetically attracted or latched position. Toeffect the latter condition each contractile spring 96 has an endanchored about one of the lugs 132 formed by slots in bracket 122 and anopposite end connected to an extension 133 from its correspondingarmature 92; and each spring 96 is tensioned for armature return whenits armature is disposed in its first or latched condit sm, V V V r. V

A horizontally elongated channel 134 U-shaped in crosssection, has upperend portions of its opposed sides 136 and 137 suitably secured to theoutside surfaces of a pair of spaced apart horizontally extending hangerplates 138 and 139 which are parallel to chassis plates 85 and 86.Plates 138 and 139 depend from chassis wall 114 to which they aresecured by a plurality of fasteners 140. Plates 138 and 139 generate achamber 142 therebetween longitudinally of the alignment of impellers 66and of interponents 90, said chamber 142 being coextensive with anelongated opening or slot 144 in wall 114 through which the interponentsextend upwardly toward said impellers. The closed end portion of channel134 is spaced from the lower ends of said hanger plates 138 and 139 andcloses qil'e l lbfiilf fr m be ow. 7. a,

Channel 134 is disposed medially of the electromagnets 94 of banks 108and 110. Its sides 136 and 137 are slotted, the slots 146 in side 136and the slots 147 in side 137 being spaced apart in horizontal alignmentlongitudinally of their respective sides, though the slots in one sideare offset horizontally from the slots in the other side.

Stands 128 are disposed in the lower end portion of chamber 142 with thearmatures in bank 108 passing through slots 146 and the armatures inbank 110 passing through slots 147. A bumper 148 extends along thebottom of channel 134 and provides a support toward which stands 128 areurged by springs 96 and against which said stands respose (as in FIG. 2)when said armatures are in their second or unlatched condition. Thebumper is held in a retainer 150 which is secured along the bottom ofchannel 134 by means of a plurality of fasteners 152 (only one of whichis shown).

Operation of the exemplary embodiment is described in at least one of myaforesaid copending and contemporaneously filed applications. Thedistinctive features of the present invention repose in the combinationof means, generally designated 154 (FIG. 3), for connectingelectromagnets 94 to a logic assembly, whereby the electromagnets can beselectively energized for operating printer 10.

Means 154 comprises a mounting board 156 (FIGS. 2 and 3) which isdisposed in a horizontal plane below chassis 29 and perpendicular tochassis plates 85 and 86. Board 156 is secured to the bottom of channel134 by the fasteners 152. From its lower surface, board 156 supports apair of component assemblies 158 and 160 (FIG. 2) of a logic system forenergizing electromagnets 94 in a meaningful succession for printing.Said component assemblies are shown schematically, the assembly forenergizing the bank 108 electromagnets being designated 158 and theassembly for energizing the bank 110 electromagnets being designated160. The components of the assemblies 158 and 160 may be integratedcircuits or miniature circuit elements. These components may includedecoders, signal amplifiers, and counting means which may be assembledin a conventional manner for converting intelligence signals from aremote station into signals which can be utilized by the printer, andimposing such signals on the windings member 104 of selectedelectromagnets 94. The details of the logic system forms no part of thepresent invention.

Each of the component assemblies 158 and 160 has a plurality of outputleads 162 (only one such lead from each assembly is shown in FIG. 2).Each lead 162 extends through circuit board 156 and is electricallyconnected to a terminal pad 164 formed on the upper surface of board 156for providing input intelligence to a corresponding one of theelectromagnets 94. Each of the component assembly also has a commonreturn 166 which projects through the circuit board 156 and iselectrically connected to a common ground land 168 formed on the uppersurface of the circuit board 156.

Circuit cards 170 and 172 are substantially identical, each being amirror image of the other. Circuit card 170 is connected to theelectromagnets 94 in bank 108 and circuit card 172 is connected to theelectromagnets 94 in bank 110. The circuit cards and the circuit board156 are orthogonally disposed, the circuit cards being.

parallel to each other and spaced apart on opposed sides of stands 128and outside of the channel 134. Circuit cards 170 and 172 are physicallysecured by any suitable means to circuit board 156, and each has aplurality of apertures to only some of which reference numerals 174(FIG. 3) have been applied. The armatures 92 of bank 108 extend throughapertures 174 in card I and the armatures 92 of bank extend throughapertures 174 in card 172. The apertures are fashioned for accommodatingrocking movement of armatures 92.

Each of the circuit cards and 172 extends longitudinally ofits array ofelectromagnets 94; and for each electromagnet in its bank there is apair of vertically aligned slots 176 and 178. The slots are disposedsuch that the slots 176 in each of the circuit cards are alignedhorizontally and the slots in 178 in each of the circuit cards arealigned horizontally below the alignment of slots 176.

A bobbin assembly 180 (FIG. 4) comprises coupled bobbins 180A and 1808and which supports each windings member 104. The inner bobbin 180A ofeach bobbin assembly has an upper pair of spring legs 182 and a lowerpair of spring legs 184. The spring legs of each bobbin assembly 180 arefashioned for snap-fit into a vertically aligned pair of slots 176 and178 for releasably mounting the windings members 104 on circuit cards170 and 172.

Bobbin 180A and outer bobbin 1808 of each bobbin assembly are connectedtogether by a living or elastic hinge 186 (FIG. 5) fashioned integrallywith their lower parts. The top side of each bobbin 1808 is fashionedwith a snap-in male element 188; and each bobbin 180A is fashioned witha cooperative female snap-in component 190 which is proportioned forreleasably receiving a male component. In consequence of the foregoing,the bobbins 180A and 1808 ofa coupled assembly may be mounted on thespindle (not shown) of a winding assembly by bending the bobbins at thehinge 186 into coaxial alignment in the direction of arrows 192 and 194(FIG. 5). Thereafter, in a single winding to form windings member 104,each pair of coupled coils 104A and 104B can be wound on the bobbins180A and 180B in a single continuous operation, thereby generating aconnecting wire segment 195 between each pair of coils 104A and 1048,and an input wire end portion 196 and an output wire end portion 198 oneach windings member. The bobbins are restored, after winding, to theiroperable configuration (FIG. 4) by bending the hinge 186 to move thebobbin opposite to the direction of arrows 192 and 194.

In such last named condition each windings member 104 is easily mountedon one of the circuit cards 170 and 172 by engaging legs 182 and 184 inslots 176 and 178. Thereafter, each circuit card then is mounted in agenerally vertical aspect (FIG. 2) by slipping the bobbins 180A and 1808of each member 180 over the core arms 106A and 1068 of a correspondingcores 106. This results in a disposition of circuit cards 170 and 172longitudinally of the alignment of the cores 106 and perpendicular tothe extension of theirelectromagnetsn Subsequently, the circuit cards170 and 172 can be physically and electrically connected to circuitboard 156 and the latter secured in its position with fasteners 152. Toattain electrical connection, each input end portion 196 is electricallyconnected to corresponding one of the electrically conductive inputlands 200 which may be fashioned in any known manner on one of thecircuit cards I70 and 172. Each output end portion 198 (FIG. 5) iselectrically connected to a respective common return conductor 202fashioned in any known manner longitudinally of each of the circuitboards 170 and 172. Lands 200 on each circuit card are horizontallyaligned longitudinally of the card and parallel to the common returnconductor 202.

A common return pad 204 at the terminal end of conductor 202 andadjacent the end of each of the circuit cards 170 and 172 iselectrically connected by known means to one of the common returnconductors 168. Each land 200 is electrically connected by a conductor206 on its circuit card to a corresponding input pad 208. The input pads208 on each circuit card are aligned along the lower edge of such cardadjacent theirjuncture with circuit board 156 and are connected by meanswhich may be known to a corresponding one of the terminals 164. i

It is observed that circuit board 156 could be obviated by mounting thecomponent assemblies 158 and 160 of the logic system in the form ofintegrated circuitry on respective circuit cards 170 and 172. This wouldentail enlargement of the printer [0, because known components could notbe accommodated within the areas of cards 170 and 172 as presentlydesigned. The exemplary assembly has minimum printer size requirementswithin the framework of-presently known technology.

As many modifications in the described construction could be conceived,and as many widely different embodiments could be made without departingfrom the spirit and scope of the claims, it is intended that all mattercontained in the accompanying specification shall be considered asillustrative only and not in a limiting sense.

1. In combination with a teleprinter of the type having aframe; aplurality of electromagnets mounted in the frame and arranged in twospaced parallel rows; an equal plurality of armatures pivotably mountedin the frame in two spaced parallel rows, each armature being associatedwith a corresponding electromagnet and individually movable from anon-printing position to a printing position in response to energizationof the corresponding electromagnet; an equal plurality of print hammersarranged in a single row, one corresponding to each print position in aline, one print hammer being associated with each armature; and meansresponsive to movement of each individual armaturefor firing theassociatd print hammer; and improved assembly of electromagnets andarmatures characterized by:

A. the electromagnets being arranged vertically beneath the printerframe in two horizontal rows, the electromagnets in the two rows beingstaggered so that the electromagnets in one row operate odd numberedprint hammers in the row of hammers and the electromagnets in the otherrow operate even numbered print hammers;

B. the armatures comprising pivoted arms mounted in the frame generallyhorizontally in two spaced parallel rows, each armature being mountedvertically beneath the associated electromagnet and having an operatingend extending inwardly toward arms of said core.

the center of the printer, the operating ends terminating in a commonvertical plane midway between the two rows of electromagnets, theoperating ends of the armatures in one row being interleaved with thoseof the other row;

C. the electromagnets comprising a plurality of vertically arrangedmagnet cores secured to the frame and depending therefrom in the twoparallel rows, a plurality of bobbin assemblies slidably received on thecores in vertical positions, and electrical operating coils wound on thebobbin assemblies:

D. a pair of printed circuit cards mounted vertically in the framebetween the cores and the operating ends of the armatures, one cardbeing associated with each row of electromagnets and armatures. thecards extending downward from positions above the tops of the bobbins topositions below the armatures, the cards having elongated verticallydisposed slots therethrough, through which the armatures extend andwhich permit pivoting movement of the armatures when the coils areoperated;

E. snap-in connecting means for physically connecting each bobbinassembly to its associated circuit card in the required position in itsrow, the cards serving to vertically position the bobbin assemblies onthe cores at the desired altitude, each card having a plurality ofprinted conductors having portions extending vertically downward to thebottom of the card and terminating in terminal pads along the bottom ofthe card, the conductors being arranged on the cards opposite to thebobbins and being electrically connected to the leads of the coils; and

F. means for connecting individual operating circuit components for theelectromagnets to the terminal pads at the bottom of the cards.

2. An assembly as recited in claim 1, wherein the connecting means (F)comprises a horizontal circuit board extending beneath the printer andfeatened to the frame in a position below and engaging the bottoms ofthe two circuit cards, the board and lower edges of the cards havingaligning means to locate the cards with respect to the board, the boardhaving printed circuit conductors along its upper surface engaging andelectrically connecting with the terminal pads on the cards, theoperating circuit components being electrically connected to the printedconductors on the circuit board and being mechanically fastened to theboard beneath the board.

3. A combination as recited in claim 2, wherein each bobbin assemblycomprises a pair of coupled together bobbins, each operating coilcomprises a pair of electrically connected coils wound on the bobbins,and each magnetic core comprises a pair of arms depending from theframe, each bobbin being positioned on one of said

1. In combination with a teleprinter of the type having a frame; aplurality of electromagnets mounted in the frame and arranged in twospaced parallel rows; an equal plurality of armatures pivotably mountedin the frame in two spaced parallel rows, each armature being associatedwith a corresponding electromagnet and individually movable from anon-printing position to a printing position in response to energizationof the corresponding electromagnet; an equal plurality of print hammersarranged in a single row, one corresponding to each print position in aline, one print hammer being associated with each armature; and meansresponsive to movement of each individual armature for firing theassociatd print hammer; and improved assembly of electromagnets andarmatures characterized by: A. the electromagnets being arrangedvertically beneath the printer frame in two horizontal rows, theelectromagnets in the two rows being staggered so that theelectromagnets in one row operate odd numbered print hammers in the rowof hammers and the electromagnets in the other row operate even numberedprint hammers; B. the armatures comprising pivoted arms mounted in theframe generally horizontally in two spaced parallel rows, each armaturebeing mounted vertically beneath the associated electromagnet and havingan operating end extending inwardly toward the center of the printer,the operating ends terminating in a common vertical plane midway betweenthe two rows of electromagnets, the operating ends of the armatures inone row being interleaved with those of the other row; C. theelectromagnets comprising a plurality of vertically arranged magnetcores secured to the frame and depending therefrom in the two parallelrows, a plurality of bobbin assemblies slidably received on the cores invertical positions, and electrical operating coils wound on the bobbinassemblies; D. a pair of printed circuit cards mounted vertically in theframe between the cores and the operating ends of the armatures, onecard being associated with each row of electromagnets and armatures, thecards extending downward from positions above the tops of the bobbins topositions below the armatures, the cards having elongated verticallydisposed slots therethrough, through which the armatures extend andwhich permit pivoting movement of the armatures when the coils areoperated; E. snap-in connecting means for physically connecting eachbobbin assembly to its associated circuit card in the required positionin its row, the cards serving to vertically position the bobbinassemblies on the cores at the desired altitude, each card having aplurality of printed conductors having portions extending verticallydownward to the bottom of the card and terminating in terminal padsalong the bottom of the card, the conductors being arranged on the cardsopposite to the bobbins and being electrically connected to the leads ofthe coils; and F. means for connecting individual operating circuitcomponents for the electromagnets to the terminal pads at the bottom ofthe cards.
 2. An assembly as recited in claim 1, wherein thE connectingmeans (F) comprises a horizontal circuit board extending beneath theprinter and featened to the frame in a position below and engaging thebottoms of the two circuit cards, the board and lower edges of the cardshaving aligning means to locate the cards with respect to the board, theboard having printed circuit conductors along its upper surface engagingand electrically connecting with the terminal pads on the cards, theoperating circuit components being electrically connected to the printedconductors on the circuit board and being mechanically fastened to theboard beneath the board.
 3. A combination as recited in claim 2, whereineach bobbin assembly comprises a pair of coupled together bobbins, eachoperating coil comprises a pair of electrically connected coils wound onthe bobbins, and each magnetic core comprises a pair of arms dependingfrom the frame, each bobbin being positioned on one of said arms of saidcore.